A method used by your friendly, self-motivated drug-dealer to try and squeeze you for more money.

When your dealer bestows upon you, out of the goodness of his heart, a free bag of better/more expensive product that makes what you usually get from him now seem like a bag of crappy-ass shit. Of course he would deny trying to Up-Sell, but is hoping to turn your usual $100 order into a $200 order, having shown you what you are missing. He might also step up the game by making sure your $100 bag now goes down in quality each time you buy, just enough to be noticed by you but not seem obviously intentional by him.